On Monday, October 22, 2018 at 4:57:58 PM UTC-4, wrote:
On Mon, 22 Oct 2018 13:32:55 -0700 (PDT), trader_4
wrote:
On Monday, October 22, 2018 at 1:40:40 PM UTC-4, trader_4 wrote:
OK, so here's the latest. Upon looking at the plumbing, I realized
that the primer bulb, even if it's leaking, can't be the problem.
It's on the after side of the carb. Fuel flows from the tank,
to the carb, out the carb, to the primer bulb suctions side, out
the primer bulb and back to the tank via the return line.
But, just to be sure, I did bypass it and the symptoms don't change.
Starts right up idles, runs up as you give it throttle, but at speed
after about 15 seconds, it just dies out. Further suspecting a fuel
problem, I tried running it with the return hose disconnected.
While it's running, no gas is coming out of the return. So, logically
what's happening, it's barely getting enough gas to run and when I
advance the throttle, there isn't enough so it quits. This is the
same problem it had ten years ago, when I gave up on it.
So, the only remaining two possibilites a
1 - The carb isn't pumping properly
2 - The fuel filter in the tank is clogged.
The fuel filter, I had out. It had a kind of red, oily look to it, I
presume from the remaining gas evaporating over ten years and the oil
and some residue being left behind. I sprayed it out with carb cleaner,
blew it out with compressed air and it looks OK from what I can tell.
I doubt that's the problem, but it's still possible that it's partially
clogged and can't flow enough. I will diagnose further.
The carb, IDK. Taking it apart it looked OK, a little residue that came
right out, no corrosion. I'm no ace with regular carbs, let alone these
two stroke gizmos. It has two plastic gaskets, one on each side. I
guess one or both vibrate to pump the fuel? One has a dime size dome
to it of the same material, no metal. The one on the other side has a
nickel size piece of
metal in the middle. IDK how flexible they are supposed to be, if they
can stretch and no longer work, etc. All I know is there isn't any
cracking, no missing pieces, they look OK, so what's wrong?
Here is a link to a rebuild kit on Ebay. The two plastic diaphragm gizmos
in mine are the two on the left side of the first/main photo. The other
similar ones are for other models. I guess I can
buy a rebuild kit. All the other pieces in mine, eg the valve, spring, etc
in that kit in mine look OK. Is there anything I should look for in those
two parts that indicate they are bad and the source of my problem?
Another question, on welch plugs, I remember on a Tecumseh, the service
manual said that after you put them in you should coat them with nail polish.
I did that. Seemed kind of nuts, like you'd think gas would dissolve it,
no? What are you supposed to do with welch plugs after you replace them?
I guess another option is just shell out $35 for a whole new carb.
TIA for any help.
Is this the regular Walbro.
It's a ZAMA used on Echo, MTD, Troy-Built, etc.
https://www.ebay.com/itm/ORIGINAL-Za...Dw0:rk:33:pf:0
Or just put 301821427313, which is the item number, in the ebay search bar.
One big screw with the mylar flappers and
4 small screws on the other side with a rubber looking diaphragm?
No, two screws on each side. The parts are shown in the rebuild kit
on Ebay. Sorry, I meant to give the link in the prior post:
https://www.ebay.com/itm/Carburetor-...n M:rk:5:pf:0
If that link doesn't work, just go to ebay and put the item number in
the search bar: 172218406466
so the diaphragm is the fuel pump and the mylar deal is the check
valves. It is a pretty simple thing. Manifold vacuum operates the
diaphragm and the check valves keep the fuel going the right way.
I guess that's what I don't understand. Those two plastic material
diaphragm things look OK to me. I wonder if there's some passage
that I didn't get to that's involved with pumping? I wouldn't
think so, the passages from the connection pipes going into the
interior are all clear. In my latest post, I said that it looks like
a lot of air is in the return line from the carb, which sounds like
something is hosed up, I would think it would be all gas.
You
can try a kit but I usually just throw a carburetor at these things. I
am about 50:50 with the kit so it is a wash.
Yes, I know what you're saying. There's so much going on inside that
damn thing.
You should get the adjusting tool tho. Sometimes you can just tweak
the HS needle and get them running right. I have a weed whacker that I
screw with all the time. Some days it runs a half a turn more open and
the next time I use it I have to close it a half turn. I also like the
manual choke because you can play with that to see if it is too rich
or too lean. Some days that weed whacker will only run with about 1/4
choke, no matter what I do with the jet. The problem is I really don't
use it much.